Motor vehicles, such as, for example, hybrid vehicles use multiple propulsion systems to provide motive power. This hybrid vehicles recharge their batteries by capturing kinetic energy via regenerative braking. When cruising or idling, some of the output of the combustion engine is fed to a generator (merely the electric motor(s) running in generator mode), which produces electricity to charge the batteries. This contrasts with all-electric cars which use batteries charged by an external source such as the grid, or a range extending trailer. Nearly all hybrid vehicles still require gasoline as their sole fuel source though diesel and other fuels such as ethanol or plant based oils have also seen occasional use.
Battery is an important energy storage device and is well known in the art. The battery converts chemical energy within its material constituents into electrical energy in the process of discharging. A rechargeable battery is generally returned to its original charged state by passing an electrical current in the opposite direction to that of the discharge. Presently, well known rechargeable battery technologies include Lithium Ion (LiON), Nickel Cadmium (NiCd), and Nickel Metal Hydride (NiMH). Each battery includes multiple cells that typically comprise electrodes and an ion conducting electrolyte therebetween. For example, the rechargeable lithium ion cell, known as a rocking chair type lithium ion battery, typically comprises essentially two electrodes, an anode and a cathode, and a non-aqueous lithium ion conducting electrolyte therebetween. The anode (negative electrode) is a carbonaceous electrode that is capable of intercalating lithium ions. The cathode (positive electrode), a lithium retentive electrode, is also capable of intercalating lithium ions. The carbon anode comprises any of the various types of carbon (e.g., graphite, coke, carbon fiber, etc.) which are capable of reversibly storing lithium species, and which are bonded to an electrochemically conductive current collector (e.g., copper foil) by means of a suitable organic binder (e.g., polyvinylidine fluoride, PVdF). The cathode comprises such materials as transition metals and chalcogenides that are bonded to an electrochemically conducted current collector (e.g., aluminum foil) by a suitable organic binder. Chalcogenide compounds include oxides, sulfides, selenides, and tellurides of such metals as vanadium, titanium, chromium, copper, molybdenum, niobium, iron, nickel, cobalt, and manganese. Lithiated transition metal oxides are, at present, the preferred positive electrode intercalation compounds. Examples of suitable cathode materials include LiMnO2, LiCoO2, LiNiO2, and LiFePO4, their solid solutions and/or their combination with other metal oxides and dopant elements, e.g., titanium, magnesium, aluminum, boron, etc.
The electrolyte in such lithium ion cells comprises a lithium salt dissolved in a non-aqueous solvent which may be (1) completely liquid, (2) an immobilized liquid (e.g., gelled or entrapped in a polymer matrix), or (3) a pure polymer. Known polymer matrices for entrapping the electrolyte include polyacrylates, polyurethanes, polydialkylsiloxanes, polymethacrylates, polyphosphazenes, polyethers, polyvinylidine fluorides, polyolefins such as polypropylene and polyethylene, and polycarbonates, and may be polymerized in situ in the presence of the electrolyte to trap the electrolyte therein as the polymerization occurs. Known polymers for pure polymer electrolyte systems include polyethylene oxide (PEO), polymethylene-polyethylene oxide (MPEO), or polyphosphazenes (PPE). Known lithium salts for this purpose include, for example, LiPF6, LiClO4, LiSCN, LiAlCl4, LiBF4, LiN(CF3SO2)2, LiCF3SO3, LiC(SO2CF3)3, LiO3SCF2CF3, LiC6F5SO3, LiCF3CO2, LiAsF6, and LiSbF6. Known organic solvents for the lithium salts include, for example, alkyl carbonates (e.g., propylene carbonate and ethylene carbonate), dialkyl carbonates, cyclic ethers, cyclic esters, glymes, lactones, formates, esters, sulfones, nitrates, and oxazoladinones. The electrolyte is incorporated into pores in a separator layer between the anode and the cathode. The separator layer may be either a microporous polyolefin membrane or a polymeric material containing a suitable ceramic or ceramic/polymer material.
Today, one of major problems that manufactures of the lithium batteries are trying to solve relates protection of the global environment. As a result, the collection of various used batteries has become more and more active. Further, local governments have legislated the recycling of batteries so that the collection and reuse of used batteries is being promoted. However, the collection and reuse of used batteries requires a large effort and cost, and as a result most used batteries are abandoned without collection or reuse. To address this problem, the use of rechargeable batteries which may be charged over and over has been promoted; using such rechargeable batteries is thus advantageous for the protection of the global environment. Nevertheless, there are drawbacks that rechargeable batteries are costly, a rechargeable battery needs a charger for recharging, a long time is often required for recharging, etc. As a result, many users choose not to use rechargeable batteries. Prior batteries formed of multiple cells have been constructed as a single unit so that if even a single cell becomes defective, the entire battery must be discarded and recycled. An example is the cylinder cell in the form of a coiled flat cell. These prior batteries also can become excessively hot during use.
Various prior art references tried to solve one or more problems associated with the aforementioned drawbacks. The United States Patent Publication No. 20040113588 to Mikuriya et al. teaches a method of recycling secondary batteries by establishing several sites or locations for receiving used secondary batteries (i.e., discharged secondary batteries) from users of the secondary batteries and handing over to the users the secondary batteries that have been processed for revitalization such as recharging. The first site conducts a predetermined inspection to classify batteries into at least two groups of different levels, those in one group that can be handed over to the user as they are, and the others in another group that need to be forwarded to the second site. The second site, which receives the secondary batteries transferred from first site, conducts another inspection to classify the batteries into another two groups of different levels, with the secondary batteries of one level being returned to the first site and with the other batteries being transferred to the third site wherein the batteries are subject to a recycling process. The method taught by the United States Patent Publication No. 200401133588 to Mikuriya et al. requires multiple redundant operations and several sites for determining levels of the batteries. Moreover, this method is still leaves the batteries which are not reusable.
Alluding to the above, there is a constant need in the area of the battery art for an improved method and system for recovering and recycling battery cells that will eliminate one or more of the aforementioned problems.